The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
A speaker is an electro-acoustic transducer that transforms electrical audio signals into sound. A traditional speaker includes a diaphragm (e.g., cone, dome, membrane, diaphragm, etc) attached to a voice coil, which is suspended in a static magnetic field. An amplifier is electrically coupled to the voice coil and provides current (i.e., signal) to the voice coil producing a magnetic field. This magnetic field interacts with the static magnetic field causing the voice coil and the diaphragm to vibrate producing sound.
The efficiency of a speaker is determined through the analysis of the speaker's conversion of electrical power from the amplifier to the emitted sound power of the speaker. Conventional speakers typically are extremely inefficient at converting electrical energy to sound energy (less than 5% of electrical energy is converted into sound energy by conventional transducers). Efforts have been made to improve speaker system power efficiencies. The efficiency of a speaker can be affected by the enclosure in which it rests. For example, U.S. Pat. No. 7,686,129 to Delgado entitled “Acoustic Horn Having Internally Raised Geometric Shapes,” filed Aug. 30, 2007 discloses a speaker that uses a particularly shaped horn to increase the overall efficiency of a speaker driver. However, horn shaped speaker enclosures still cause undesirable destructive interference in the sound waves projected from the driver of the speaker. Because of this behavior, this horn does not perform equally well across the entire range of frequencies that the speaker is capable of delivering.
In addition, U.S. Pat. No. 6,055,320 to Wiener et al. entitled “Directional Horn Speaker System,” filed Feb. 26, 1998 discloses a directional speaker. In doing so, it describes several attempts to increase audio quality. For example, an in-line phase plug is mounted in front of the speaker driver for manipulating the wave front of sound waves produced by the speaker driver. However, the invention fails to provide improvements of efficiency relative to sensitivity and clarity. This is mainly due to the fact that as one improves the sensitivity and clarity of a speaker system, the power loss increases, and hence, the overall efficiency of the system is degraded.
U.S. Pat. No. 4,421,200 to Ferralli et al. entitled “Elliptically Shaped Transducer Enclosure,” filed Dec. 16, 1981, provides for an enclosure incorporating an acoustically reflective shell. The elliptical shapes share one common focus and each has one distinct focus. Even though this does improve efficiency over prior absorber-type enclosures, there still remain inefficiencies in the shape with respect to output power as compared to input electrical signals.
However, the above-mentioned patents still fail to dramatically improve the power efficiency of speaker systems. Thus, there remains a need to further improve speaker efficiency.
All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.